What sensible things can be written based on the Net (Nodejs) module?

Question

JavaScript

I want to write a small TCP server to consolidate my knowledge of the NET module.
Please advise what interesting things can be written using the Net module, as a burning tool?
PS: only native nodejs modules can be used (everything except http, http/2, https)

Answer 1

For example chat, web socket server, web server or any other web application.

Answer 2

You can invent JSON RPC for communication between services